Answer this question truthfully
### Question: What causes Non-Hodgkin lymphoma?
### Response: White blood cells called lymphocytes are found in lymph tissues. They help prevent infections. Most lymphomas start in a type of white blood cells called B lymphocytes, or B cells.
For most patients, the cause of this cancer is unknown. However, lymphomas may develop in people with weakened immune systems. For example, the risk of lymphoma increases after an organ transplant or in people with HIV infection.
There are many different types of non-Hodgkin's lymphoma (NHL). It is grouped according to how fast the cancer spreads.
The cancer may be low grade (slow growing), intermediate grade, or high grade (fast growing). Burkitt's lymphoma is an example of a high-grade lymphoma. Follicular lymphoma is a low-grade lymphoma. The cancer is further grouped by how the cells look under the microscope, for example, if there are certain proteins or genetic markers present.
According to the American Cancer Society, a person has a 1 in 50 chance of developing non-Hodgkin's lymphoma. NHL most often affects adults. However, children can get some forms of lymphoma. You are more likely to get lymphoma if you have a weakened immune system or have had an organ transplant.
This type of cancer is slightly more common in men than in women.